(1) FIELD OF THE INVENTION
The present invention relates to lights and, more particularly, warning lights having a wide angle radiation pattern, particularly in a band lying about a single plane. Accordingly, the general objects of the present invention are to provide novel and improved devices of such character.
(2) Description of the Prior Art OF ART
Warning lights which are employed on emergency vehicles, such as police cars, ambulances, fire trucks, motorcycles and the like, are intended to perform the function of warning of the approach of the vehicle. This requires that the light energy which is produced be intermittent, i.e., be emitted in bursts or pulses, be concentrated in a horizontal plane parallel to the surface over which the vehicle is traveling and be radiated in a wide angle pattern so as to alert traffic approaching from the sides, traffic approaching from the direction in which the vehicle is headed and traffic being overtaken. Such warning lights often comprise a revolving lamp or mirror, but may alternatively comprise a xenon flash tube and cooperating lens and reflector. The prior art warning lights can be relatively expensive to manufacture. An additional drawback of many prior art warning lights is the lack of volumetric efficiency of the light. A further drawback of prior warning lights resides in their inability to interchangeably employ, as the light source, incandescent, i.e., halogen, lamps and gaseous, i.e., xenon, discharge tubes.
A number of improved lights having particular applicability in connection with warning lights on emergency vehicles have recently been introduced. Many such lights employ xenon flash tubes and have found wide popularity. For example, U.S. Pat. No. 4,792,717, which is assigned to the assignee of the present invention, discloses a compact wide-angle warning light. The warning light of U.S. Pat. No. 4,792,717 comprises a unique concave reflector, a lens and a light emitter in the form of an elongated xenon flash tube. The reflector comprises a linear section having side walls which are at least in part parabolic, the linear section being disposed between parabolic dish end sections. The lens is preferably provided with spatially displaced parallel light spreaders for directing the emitted light.